An experimental and numerical survey into the potential of hybrid foams

Hybrid foams are composite materials consisting of two foamed constitutive materials. Compared to conventional mono material foams, hybrid foams have the advantage that their material properties can be adapted more easily to comply with any kinds of prescribed requirements deriving from the intended structural application. The present study is concerned with a survey of the mechanical properties of a variety of hybrid foams with both, interpenetrating and particulate microstructures. As constituent foams, polymeric, metallic and ceramic foams of different types are considered. In an experimental survey, the mechanical response of the hybrid foams is characterized under compression with loading rates covering the entire spectrum from quasi-static conditions up into the high rate regime. The experimental investigation is complemented by a numerical simulation using a hierarchical homogenization procedure to predict the effective material properties numerically. The experimental and numerical results reveal that the hybrid foam concept provides the opportunity to design lightweight cellular solids with effective mechanical properties in a wide range. The optimization potential is demonstrated in a case study considering the design of a material for a bird-strike protection system for commercial aviation.